Friday, 24 May 2024
webAIRS Information Threads

Current Journal Publications

Personal experience may be the best teacher, and learning from clinical incidents in one’s own practice very likely has a greater impact on future behaviour than hearing or reading about the experience of others. Yet relying on personal experience would be a very slow process to cover the wide range of potential clinical incidents that could occur. Our aim as anaesthetists is to avoid clinical incidents wherever possible, whether they involve harm, fortuitous no harm, or a crisis. To this end we benefit by hearing about clinical incidents experienced by our colleagues. ..............................

In this issue of Anaesthesia and Intensive Care, there are four papers reporting data obtained from the webAIRS database of voluntary de-identified on-line reports of clinical incidents in Australia and New Zealand. 


Gibbs NM.

There were 684 perioperative cardiac arrests reported to webAIRS between September 2009 and March 2022. The majority involved patients older than 60 years, classified as American Society of Anesthesiologists Physical Status 3 to 5, undergoing an emergency or major procedure. The most common precipitants included airway events, cardiovascular events, massive blood loss. medication issues, and sepsis. The highest mortality rate was 54% of the 46 cases in the miscellaneous category (this included 34 cases of severe sepsis, which had a mortality of 65%). This was followed by cardiovascular precipitants (n = 424) in which there were 147 deaths (35% mortality): these precipitants included blood loss (53%), embolism (61%) and myocardial infarction (70%). Airway and breathing events accounted for 25% and anaphylaxis 8%.

Bright MR, Endlich Y, King ZD, White LD, Concha Blamey SI, Culwick MD.

Regional anaesthesia is an essential tool in the armamentarium for paediatric anaesthesia. While largely safe and effective, a range of serious yet preventable adverse events can occur. Incidence and risk factors have been described, but few detailed case series exist relating to paediatric regional anaesthesia. Paediatric perioperative events and their outcomes were reviewed from the regional anaesthesia reports among the first 8000 reports to the webAIRS database. Please click the link below to read the full article in the journal Anaesthesia and Intensive Care 2023.

Manisha Mistry and Yasmin Endlich

Anaesthesia for caesarean section occurs commonly and places specific demands on anaesthetists. We analysed 469 narratives concerning anaesthesia for caesarean section, entered by Australian and New Zealand anaesthetists into the webAIRS incident reporting system between 2009 and 2022. To read the full article click in the link below.

Eley VA, Culwick MD, Dennis AT.

Corneal abrasions are an uncommon complication of anaesthesia. The aim of this study was to identify potential risk factors, treatment and outcomes associated with corneal abrasions reported to the web-based anaesthesia incident reporting system (webAIRS), a voluntary de-identified anaesthesia incident reporting system in Australia and New Zealand, from 2009 to 2021. There were 43 such cases of corneal abrasions reported to webAIRS over this period. The most common postoperative finding was a painful eye. Common features included older patients, individuals with pre-existing eye conditions, general anaesthesia and procedures longer than 60 minutes. Most cases were treated with a combination of lubricating eye drops or aqueous antibiotic eye drops. The findings indicate that patients who sustain a perioperative corneal abrasion can be reassured that in many cases it will heal within 48 hours, but they should seek earlier review if symptoms persist or deteriorate. None of the cases in this series resulted in permanent harm. Well established eye protective measures are important to utilise throughout the perioperative period, including the time until the patient has recovered in the post-anaesthesia care unit.

Matthew Bright, Leigh White, Sandra Concha Blamey, Yasmin Endlich and Martin Culwick

Medication error is a well-recognised cause of harm to patients undergoing anaesthesia. From the first 4,000 reports in the webAIRS anaesthetic incident reporting system, we identified 462 reports of medication errors. These reports were reviewed iteratively by several reviewers paying particular attention to their narratives. The commonest error category was incorrect dose (29.4%), followed by substitution (28.1%), incorrect route (7.6%), omission (6.5%), inappropriate choice (5.8%), repetition (5.4%), insertion (4.1%), wrong timing (3.5%), wrong patient (1.5%), wrong side (1.5%), and others (6.5%). Most (58.9%) of the errors resulted in at least some harm (20.8% mild, 31.0% moderate and 7.1% severe). Contributing factors to the medication errors included the presence of look-alike medications, storage of medications in the incorrect compartment, inadequate labelling of medications, pressure of time, anaesthetist fatigue, unfamiliarity with the medication, distraction, involvement of multiple people, and poor communication. These data add to current evidence suggesting a persistent and concerning failure to effectively address medication safety in anaesthesia. The wide variation in the nature of the errors and contributing factors underline the need for increased systematic and multifaceted efforts underpinned by a strengthening of the current focus on safety culture to improve medication safety in anaesthesia. This will require the concerted and committed engagement of all concerned, from practitioners at the clinical workface, to those who fund and manage healthcare.

Anaesthesia and Intensive Care 2021, Released online December 2021.

Jee-Young Kim, Matthew Moore, Martin Culwick, Jacqueline Hannam, Craig Webster and Alan Merry.

Earlier Journal Publications

Sugammadex has been used for over 10 years in Australia and New Zealand. During this time, there have been numerous reports of the use of sugammadex as both a treatment and cause of critical events in anaesthesia. 116 events were identified where the reporter implicated sugammadex as a cause (23 cases) and a treatment (93 cases) of a critical event in anaesthesia. These reports outline that sugammadex can be a potential trigger for anaphylaxis and that it’s use has been associated with the development of significant bradycardia. They also illustrate that sugammadex can be used to treat residual paralysis and deep neuromuscular block and can rescue a “Can’t Intubate, Can’t Oxygenate” scenario, providing support for the use and ready availability of sugammadex in hospital operating theatres.

Dr Benjamin L Olesnicky, Dr Rosie Trumper, Dr Vanessa Chen, Dr Martin Culwick

Purpose of Review: This article proposes a standardized framework for color-coding states of criticality in clinical situations and their respective escalated responses.

Recent Findings:  The first level is a green zone representing a ‘safe’ space (to proceed), where any hazards are controlled, latent, or undetectable. The second is an amber zone, where hazards are known to be present, but one can proceed with caution and increased vigilance, and where defences are used to prevent escalation to a crisis. In the red phase - a state of crisis - a hazard is realized, clear and present. This is a time to decide what actions are required to mitigate the threat.  Next, a blue phase refers to a life-threatening emergency, where harm is evident and compounding upon itself, and immediate rescue action is needed to avert an irreversible outcome. Finally, dark grey represents the aftermath, where the situation has either stabilized or progressed to its final outcome - a time to reflect and learn.

Summary: A standardized color-coding system for assessing and responding to escalating levels of criticality has implications for clinical practice and adverse event reporting systems. 

Current Opinion in Anesthesiology,  Published December 2021


Stavros Prineas, Martin Culwick and Yasmin Endlich.


Published reports of uvular necrosis are uncommon and it is possibly an under-reported complication of oropharyngeal manipulation. Uvular necrosis is thought to develop due to ischaemia secondary to mechanical compression of the uvula from oropharyngeal devices. Patients typically present with symptoms of a sore throat within 48 hours postoperatively. It is unclear whether there are any preventable factors, or any specific management strategies that might reduce this complication. Treatment is most commonly conservative management, including observation and simple analgesia. We present 13 cases of uvular injury that were reported to a web-based anaesthesia incident reporting system (webAIRS), a voluntary de-identified anaesthesia incident reporting system in Australia and New Zealand. While the postoperative findings varied, sore throat was the most frequent symptom. Most of the cases resolved spontaneously; the remainder with supportive treatment only. The findings suggest that patients who sustain a uvular injury can be reassured, but they should be advised to seek review early if sore throat persists or any difficulty with breathing develops.

Matthew R Bright, Sandra I Concha Blamey, Linda A Beckmann, Martin D Culwick

A review of the first 4000 reports to the webAIRS anaesthesia incident reporting database was performed to analyse cases reported as difficult or failed intubation. Despite advances and significant developments in airway management strategies, difficult and failed intubation still occurs. Although not all incidents are predictable, nor are all preventable, the information provided by this analysis might assist with future planning, preparation and management of difficult intubation.

Yasmin Endlich, Julie Lee and Martin Culwick.

The Bowtie diagram combines the features of a fault tree and an event tree with the adverse event, known as the Top Event separating the two sections. The fault tree is similar in concept to a Swiss Cheese diagram and the event tree similar in concept to an emergency management algorithm. Preventive barriers and escalation measures are used to detect and trap abnormal states. If these fail, the event proceeds to a crisis, leading to the Top Event, a time for making decisions. A recovery state follows, which depicts an emergency state mandating immediate life or limb-saving management to recover from the crisis. Finally, in the aftermath state, a time for reflection and learning, ultimate outcomes are shown in the right-hand column. Current Opinion in Anaesthesiology: December 2020 - Volume 33 - Issue 6 - p 808-814

Culwick, Martin; Endlich, Yasmin; and Prineas, Stavros.

This audit of airway incidents was conducted over six months in 12 tertiary level hospitals across Australia and New Zealand. During that time, 131,233 patients had airway management and 111 reports were submitted (incidence 0.08%). The airway incidents included a combination of difficult airway management (83), oxygen desaturation (58), aspiration (19), regurgitation (14), laryngospasm (16), airway bleeding (10), bronchospasm (5) and dental injury (4), which gave a total of 209 events in 111 reports. Most incidents occurred during general anaesthesia (GA; 83.8%) and normal working hours (81.1%). Forty-three percent were associated with head and neck surgery and 12.6% with upper abdominal procedures. Of these patients, 52% required further medical treatment or additional procedures and 16.2% required unplanned admission to an intensive care unit or a high dependency unit. A total of 31.5% of patients suffered from temporary harm and 1.8% from permanent harm. There was one death. The factors associated with a high relative risk (RR) of an airway incident included American Society of Anesthesiologists Physical Status (ASA PS) (ASA PS 2 versus 1, RR 1.75; ASA PS 3 versus 1, RR 3.56; ASA PS 4 versus 1, RR 6.1), and emergency surgery (RR 2.16 compared with elective). Sedation and monitored anaesthesia care were associated with lower RRs (RR 0.49 and RR 0.73 versus GA, respectively). Inadequate airway assessment, poor judgement and poor planning appeared to be contributors to these events. Future teaching and research should focus on these areas to further improve airway management and patient safety.

Yasmin Endlich, Linda Beckmann, Siu-Wai Choi and Martin Culwick

Summary: HFNO is a valuable addition to the techniques available for managing the oxygenation of patients in various anesthetic situations. Given its potential to deliver large quantities of oxygen per unit time to a source of ignition, there is particular need for vigilance in respect to potential fires whenever HFNO is used. The risk of fire must be kept firmly in mind whenever surgery is performed around the head and neck, whether supplementary oxygen is used or not.

Dr M.Culwick and Prof.Alan Merry

Unexpected difficult airways are always challenging. This article captures the information regarding difficult airway in an easy to understand Bowtie Diagram.................. Published in Australasian Anaesthesia 2019.

Yasmin Endlich and Martin Culwick

The first 4000 reports to the webAIRS anaesthesia incident reporting database were used to evaluate pulmonary aspiration in patients undergoing procedures under general anaesthesia or sedation. Demographic data, predisposing factors, outcome and potential preventative measures were evaluated. In these reports, 121 cases of aspiration were identified. Aspirated substances included gastric contents, bile type fluids, blood and solids; 60 (49.6%) patients were admitted to the intensive care unit/high dependency unit, and 43 (35.5%) required mechanical ventilation. Aspiration was associated with significant harm in >50% of reports, and eight (6.6%) patients died.

Michal T Kluger, Martin D Culwick, Matthew M Moore and Alan F Merry

WebAIRS has received a number of cases where oxygen pooled under the drapes during head and neck procedures has lead to a fire. Two of these involved high flow nasal oxygen (HFNO). This article describes the two cases invloving HFNO. In summary, it is advisable that anaesthetists use the lowest FiO2 possible to support the patient’s oxygen saturation at a safe level. Close communication between surgeons, anaesthetists and nursing staff throughout these procedures is recommended. Oxygen pooling under the drapes should be avoided by providing good airflow around the sterile area. The possible use of suction to scavenge high oxygen pockets trapped under drapes and in contact with the patient should also be considered.

K.B. Greenland M. Stokan and M. Culwick

This cross-sectional overview of the second 4000 incidents reported to webAIRS has findings that are very similar to the previous overview of the first 4000 incidents.  The distribution of patient age, body mass index, and American Society of Anesthesiologists’s Physical Status was similar, as was anaesthetist gender, grade, location, and time of day of incidents.  About 35% of incidents occurred during non-elective procedures (versus 33% in the first 4000 incidents).  The proportion of incidents in the various main categories was also similar, with respiratory/airway being most common, followed by cardiovascular, medication-related, and medical device or equipment-related incidents.  Together these categories made up about 78% of all incidents in both overviews.  The immediate outcome was comparable with reports of harm in about a quarter of incidents and a similar rate of deaths (4.7% versus 4.2%).  However, the proportion of patients who had received total intravenous anaesthesia was higher (17.6% versus 7.7%) and the proportion of patients who received combined intravenous and inhalational anaesthesia was lower (52.3% versus 58.4%), as was the proportion receiving local anaesthesia alone (1.6% versus 6.7%).  There was a small increase in the number of incidents resulting in unplanned admission to a high dependence or intensive care unit (18.1% versus 13.5%).  It is not clear whether these differences represent trends or random observations.  About 48% of incidents were considered preventable by the reporters (versus 52% in the first 4000).  These findings support continued emphasis on human and system factors to promote and improve patient safety in anaesthesia care.

Neville. M. Gibbs, Martin Culwick, Yasmin Endlich, Alan. F. Merry

Summary: ‘Can’t intubate, can’t oxygenate’ (CICO) scenario is a rare anesthesia crisis for which the management has been suboptimal in the past. Inadequacy and disorganization of airway equipment have been identified as one of the latent factors that contribute to the failure of CICO management. We initiated a quality improvement project to review the equipment aspect of CICO management in our department. We revised our emergency front of neck access (FONA) airway equipment based on available evidence and organized the equipment with custom-made CICO kits. The CICO kits could potentially streamline management, and institutionally standardized equipment across all critical care departments. Our approach may serve as a practical guide for implementation of standard practice for CICO management.

Foong, W.M., Wyssusek, K.H., Culwick, M.D. and van Zundert, A.A.J.

Summary: In preparation for a case, an anaesthetist opened a 20 ml glass vial of propofol and aspirated the propofol into a syringe via a blunt drawing-up needle. Increased resistance was felt with aspiration. On inspection, a shard of glass was found at the tip of the drawing-up needle. The shard was presumed to be from the propofol ampoule, and to have fallen into the solution upon snapping open its glass tip. This illustrative case raises the issue of contamination of drugs by particles introduced during the drawing-up process. It also highlights the possibility that during the drawing-up process, intravenous drugs may become contaminated not just with particles, but with microorganisms on the surface of the particles. In this article, we discuss relevant recent research of the implications of this type of drug contamination. We draw attention to the need for meticulous care in drawing up and administering intravenous drugs during anaesthesia, particularly propofol.

AF Merry, DA Gargiulo, LE Fry

The aim of this study was to analyse the incidents related to awareness during general anaesthesia in the first 4,000 cases reported to webAIRS—an anaesthetic incident reporting system established in Australia and New Zealand in 2009. Included incidents were those in which the reporter selected “neurological” as the main category and “awareness/dreaming/nightmares” as a subcategory, those where the narrative report included the word “awareness” and those identified by the authors as possibly relevant to awareness. Sixty-one awareness-related incidents were analysed: 16 were classified as “awareness”, 31 were classified as “no awareness but increased risk of awareness” and 14 were classified as “no awareness and no increased risk of awareness”. Among 47 incidents in the former two categories, 42 (89%) were associated with low anaesthetic delivery and 24 (51%) were associated with signs of intraoperative wakefulness. Memory of intraoperative events caused significant ongoing distress for five of the 16 awareness patients. Patients continue to be put at risk of awareness by a range of well-described errors (such as syringe swaps) but also by some new errors related to recently introduced anaesthetic equipment, such as electronic anaesthesia workstations.

K Leslie, MD Culwick, H Reynolds, JA Hannam, AF Merry

Too many patients are harmed by healthcare intended to help them. Anaesthesia, an essential component of healthcare, is thought to have become very safe in recent years—at least in high income countries. Indeed, anaesthetists are often held up as leaders in the pursuit of patient safety. It is easy to forget that this was not always the case: a seminal paper by Macintosh, drawing attention to basic failures in anaesthetic practice that were then contributing to avoidable deaths, is worth reading. Macintosh’s paper is surprisingly forthright and honest, and was an early example of the importance of learning from mistakes in healthcare. We have certainly made progress since then, but there is no room for complacency. The NAP43 and NAP54 publications are timely reminders that serious complications do still occur in anaesthesia today, and that they often involve relatively healthy individuals undergoing apparently straightforward surgical procedures under the care of well-trained anaesthetists. We (as anaesthetists) may be generic leaders in patient safety, but there is still much for us to learn about safety in our own speciality. The need to continue learning and improving is the primary reason for reporting and reviewing incidents. To read more click on the link below.

AF Merry, B Henderson

The article in the Medial Observer is based upon the recent article published in Anaesthesia and Intensive Care relating to risk and harm reported in the first 4000 incidents analysed by ANZTADC. It was evident that the Medical Observer article had sensationalised the findings. DR Neville Gibbs (ANZTADC Chair) responded to assure the readers that anaesthesia is safe when the number of anaesthetics per year is taken into account, and that the aim of the study is to improve patient safety during anaesthesia. The following points were made in the response.

  • The aim of anaesthetists is to avoid all incidents. That is why studies of this type are undertaken.
  • Patients should be reassured that there are well over 2.5 million anaesthetics each year in Australia and New Zealand, or over 50,000 each week, so the chance of a patient having any incident at all is extremely small.
  • The majority of incidents result in no harm.
  • Further analysis of the 4000 incidents in the webAIRS database will investigate the relationship between harm and preventability, and ways to further improve patient safety.
  • This type of activity is an example of many many safety measures and initiatives that support an extremely high level of anaesthetic safety in Australia and New Zealand.

If you have any further points that you would like to contribute please contact
There is a link to the article below.

M Culwick

Patient and procedural factors associated with an increased risk of harm or death in the first 4,000 incidents reported to webAIRS. Anaesthesia and Intensive Care, Volume 45, Issue 2, Pages
This report describes an analysis of patient and procedural factors associated with a higher proportion of harm or death versus no harm in the first 4,000 incidents reported to webAIRS. The report is supplementary to a previous cross-sectional report on the first 4,000 incidents reported to webAIRS.

NM Gibbs, MD Culwick, AF Merry

A cross-sectional overview of the first 4,000 incidents reported to webAIRS, a de-identified web-based anaesthesia incident reporting system in Australia and New Zealand. Published in January 2017.

NM Gibbs, MD Culwick, AF Merry

Summary The role of preoperative fasting is well established in current anaesthetic practice with different guidelines for clear fluids and food. However, chewing gum may not be categorised as either food or drink by some patients, and may not always be specified in instructions given to patients about preoperative fasting. The aim of this paper was to review anaesthesia incidents involving gum chewing reported to webAIRS to obtain information on the risks, if any, of gum chewing during the preoperative fasting period. There were nine incidents involving chewing gum reported between late 2009 and early 2015. There were no adverse outcomes from the nine incidents other than postponement of surgery in three cases and cancellation in one. In particular, there were no reports of aspiration or airway obstruction. Nevertheless, there were five cases in which the gum was not detected preoperatively and was found in the patient’s mouth either intraoperatively or postoperatively. These cases of undetected gum occurred despite patient and staff compliance with their current preoperative checklists. While the risk of increased gastric secretions related to chewing gum preoperatively are not known, the potential for airway obstruction if the gum is not detected and removed preoperatively is very real. We recommend that patients should be specifically advised to avoid gum chewing once fasting from clear fluids is commenced, and that a specific question regarding the presence of chewing gum should be added to all preoperative checklists.

NM Gibbs, S Shanmugam, G Goulding, K Taraporewalla, MD Culwick


“We cannot fix what we do not know.”

Preventing adverse events requires an understanding of current practice, and then strategies to influence that practice to produce the desired result. This typically requires learning from previous adverse events or “near misses,” and then adjusting the system to prevent adverse events from occurring again.

A patient safety incident is defined by the World Health Organization as an event or circumstance, which could have resulted, or did result, in unnecessary harm to a patient.  A near miss is defined as an incident that did not reach the patient but reasonably could have.

Most medical errors are multifactorial, and many individual errors must usually align in order to cause harm. There are two approaches to reducing adverse events and harm to patients. The first approach is reactionary, and consists of analysis, dissection, and changes designed to prevent the same (or a similar set of) circumstances from resulting in harm. The second approach is to proactively analyse changes or systems, sometimes before they are implemented, for opportunities to improve the system and decrease the error rate.

 A failure mode and effects analysis (FMEA) is an example of one such tool (described in the chapter).

A causal tree and an event tree can be fused to create a bow-tie diagram, which pictorially takes the shape of a bow tie (described in the chapter).

The book is available through the ANZCA library. (Link below for further details to the book and then view chapter 9).

Patrick J. Guffey and Martin Culwick.

Bow-tie analysis is a risk analysis and management tool that has been readily adopted into routine practice in many high reliability industries such as engineering, aviation and emergency services. However, it has received little exposure so far in healthcare. Nevertheless, its simplicity, versatility, and pictorial display may have benefits for the analysis of a range of healthcare risks, including complex and multiple risks and their interactions. Bow-tie diagrams are a combination of a fault tree and an event tree, which when combined take the shape of a bow tie. Central to bow-tie methodology is the concept of an undesired or ‘Top Event’, which occurs if a hazard progresses past all prevention controls. Top Events may also occasionally occur idiosyncratically. Irrespective of the cause of a Top Event, mitigation and recovery controls may influence the outcome. Hence the relationship of hazard to outcome can be viewed in one diagram along with possible causal sequences or accident trajectories. Potential uses for bow-tie diagrams in anaesthesia risk management include improved understanding of anaesthesia hazards and risks, pre-emptive identification of absent or inadequate hazard controls, investigation of clinical incidents, teaching anaesthesia risk management, and demonstrating risk management strategies to third parties when required.

MD Culwick, AF Merry, DM Clarke, K Taraporewalla, NM Gibbs

Brief History We cannot fix what we do not know. From the very first anesthetic, there have been reported cases of harm.1 Early on, these reports were often anecdotal, passed by word-ofmouth or letter among a small group of colleagues. Over time, anesthesiologists began to focus on the most devastating “incidents” associated with anesthesia and unexplained deaths. One of the first large studies on anesthesia mortality reviewed 599,548 patients who had received anesthesia2 and noted an overall mortality related partly or wholly to anesthesia of 1 in 3000 cases. The authors noted that there was an increase in anesthesia death rate when muscle relaxants were used, but accepted that there was no evidence that this was directly related to the drugs. The mechanism of these deaths was frequently cardiovascular collapse and the authors implied that this might have been because of the ganglion-blocking effect of these drugs. The relaxants used at that time included tubocurarine, decamethonium, succinylcholine, gallamine, and di-methyl tubocurarine. Anesthesiology departments throughout the world were encouraged to hold local mortality review meetings that subsequently included reviews of morbidity as well.This paper reviews the ethical considerations, the barriers to reporting and several successful local and international incident reporting systems.

Guffey, Patrick J.; Culwick, Martin; Merry, Alan F.

The safe administration of drugs to patients lies at the core of anaesthetic practice. Anaesthesia is unique as a medical specialty where a single doctor routinely prescribes, dispenses, prepares then administers multiple medications, often within an urgent or emergent time scale. Compound this with the fact that many of the medications used are potentially life threatening if given erroneously, it becomes clear that medication safety is fundamental to modern anaesthesia. The introduction of pre-filled metaraminol and pre-filled ephedrine syringes in the RBWH main operating theatres has been highly successful. It has resulted in a decreased overall cost of these drugs to the department, with further improvements in the cost saving margins expected. Published in Australasian Anaesthesia (The Blue Book) 2013.

Nathan Goodrick, Torben Wentrup, Geoffrey Messer, Patricia Gleeson, Martin Culwick and Genevieve Goulding.


This paper presents a case study chronicling the development of WebAIRS, an Australasian national anaesthetic

incident reporting database for health care practitioners. WebAIRS is an example of the multidisciplinary nature

of the IS discipline, incorporating IS theories, tools and principles in the creation of an IT artefact with

significant real world application. This case study introduces the background of the project and the motivations

for its conception including the need for critical incident reporting in anaesthesia, the process of its development

using IT students and the problems identified following its national release among the anaesthetic community.

The paper demonstrates the evolution of contemporary IS research and the IT artefact, and how each can be

crucial foundations for hospitals of the future. 

Timbrell, Greg, Culwick, Martin, Delaney, Patrick, Culwick, David, Goulding, Genevieve and Merry, Alan